CDX2 transactivates ST6GalNAc-I. Three different luciferase reporter plasmids containing ~1.6, ~0.8 and ~0.3 kb genomic fragments upstream of the human ST6GalNAc-I start codon were tested independently in two gastric carcinoma cell lines, AGS and MKN45, in combination with a human CDX2 expression vector or the corresponding control empty vector. Another set of fragments comprising independent and combined mutations of the most proximal sites (BR5, BR6 and BR7) were also used. The CDX2-putative-binding regions are identified as small bars in the fragments, and the order corresponds to the one shown in Figure 4a. As a control, CDX2 promoter itself was used. The values obtained were corrected for transfection efficiency with Renilla luciferase activity, and results are expressed as fold induction compared with values obtained for the empty vector (here normalized to 1). The results are expressed as mean±s.d. of at least six values from at least two experiments performed in triplicate for each fragment (*P<0.05 and **P<0.01).